<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script>
    var a = 10;
    console.log(a);
    var a = 10.2;
    console.log(a);
    var a = true;
    console.log(a);
    var a = "wtm";
    console.log(a);
    var a = 12;
    console.log(a);
    a = 14;
    console.log(a);
    //变量声明 ，可声明不同类型变量，也可重复声明
    let x=1;
    console.log(x);
     let x=2;
    console.log(x);//let类型变量不可重复声明
    const y=3;
    y=4;
    //const类型变量不可重复声明,不可修改


</script>
</body>
</html>